MXPA99001074A - Arran motor - Google Patents

Abstract

The present invention relates to a starter motor, characterized in that it comprises: an output shaft to which rotational force is transmitted from a motor through a planetary gear device, a pinion movement cylinder, fitted snugly on the output shaft of axially slidable manner of the output shaft, a pinion removably mounted on an outer peripheral portion of the pinion movement cylinder on the outer peripheral portion of the pinion movement cylinder, and a bracket that supports the pinion movement cylinder rotatably and slidably.

Description

STARTING MOTOR BACKGROUND OF THE INVENTION Field of the Invention The present invention relates to a starter motor, that is to say a starting device for an automotive engine, and in particular to a starter motor in which the rotational force of a motor is transmitted through a planetary gear device to an output tree.

Description of Related Art Figure 2 is a cross-sectional view showing an example of a starter used to start an automotive engine, which is relevant to the present invention. As illustrated, a central gear 5a is integrally formed on an armature shaft 5 of a direct current motor (D.C.) which generates a rotational force to start a motor (not shown). A plurality of planetary gears 6a are provided around the central gear 5a to which rotational force is introduced from the armature shaft 5 of the D.C. The planetary gears 6a mesh with the central gear 5a and can rotate around the respective support bolts 6c. The rear end portions of the support bolts 6c are connected to an output shaft 7 having a flange 6b which also serves as a carrier of a planetary gear device 6. The output shaft 7 is positioned coaxially to the armature shaft 5 at the front end (i.e., the opposite end from the flange 6b) of the output shaft 7 which passes through a conduit 2 (i.e., the opening portion). of a front bracket 1) to externally extend the starter motor. A pinion movement cylinder 4 is provided within the front bracket 1 and is supported by a bearing 3 adjustably mounted on the front bracket 1. A pinion gear 4a is formed on the outer periphery of the front end portion of the pinion movement cylinder 4 so that it is engageable with a ring gear of the motor (not shown). This pinion movement cylinder 4 can be moved axially through the conduit 2, so that the pinion gear 4a externally retractably protrudes from the starter motor to be engaged with the ring gear. A collar or sleeve 12, which is a bearing, is tightly secured to the inner periphery of the pinion movement cylinder 4. The output shaft 7 is inserted snugly within the collar 12, and is slidably supported by it. A retainer 13 for restricting the axial displacement of the pinion movement cylinder 4 is provided in the front end portion of the output shaft 7. The retainer 13 is fixed to the output shaft 7 by a retaining ring. On the outer periphery of the output shaft 7 and between the flange 6b and the collar 12 of the insertion portion, a helical groove 7a is formed which axially twists and slides on a clutch 8 with free rotation. A displacement lever 10 is inserted on a cylindrical member 11 attached to the clutch outlet 8a so that the displacement lever 10 is pivotably driven by the action of an electromagnetic switch 9, whereby it moves the clutch 8 of free rotation axially. from the output shaft 7 towards the retainer 13 together with the pinion movement cylinder 4 also used as an inner clutch 8b of the free-wheel clutch 8. The related starter is assembled so that the front bracket 1 to which the bearing 3 is tightly mounted is mounted around the pinion movement cylinder 4 from the side pinion gear 4a. Therefore, the outer diameter of the pinion gear 4a formed on the outer periphery of the front end of the pinion movement cylinder 4 can not be made larger than the outer diameter of the surface 4b slidably supported by the pinion movement cylinder 4. which is supported by the bearing 3. Furthermore, in a case where the number of teeth of the pinion gear 4a is required, the pinion movement cylinder 4 in its entirety must be replaced while the outer diameter of the slidably supported surface 4b must be kept larger than the outer diameter of the pinion gear 4a. Accordingly, as the outer diameter of the pinion gear 4a becomes increasingly larger, the outer diameter of the surface 4b slidably supported by the pinion movement cylinder 4 becomes larger, which returns to the pinion motion cylinder 4. Larger in size and weight.

BRIEF DESCRIPTION OF THE INVENTION The present invention has been made in order to solve the problems indicated above found in the related starter motors. Accordingly, an object of the present invention is to provide a starter motor which is simple in structure, and which allows the required selection of the number of teeth of a pinion without changing the outer diameter of a slidably supported surface of the movement cylinder. of pinion, and which can prevent the removal of the pinion. A starter according to the present invention includes: an output shaft to which rotational force of a motor is transmitted through a planetary gear device; a pinion-moving cylinder mounted snugly on the output shaft so that it can be axially slidable from the output shaft; a pinion removably mounted on the outer peripheral portion of the pinion movement cylinder; a pinion retaining means for retaining the pinion on the outer peripheral portion of the pinion movement cylinder; and a bracket that supports the pinion movement cylinder rotatably and slidably. In the starter motor according to the present invention, the pinion retaining means includes a pinion retainer provided in contact with the pinion, and a retaining ring fixed to a retaining slot provided on the outer peripheral portion of the movement cylinder. of pinion. In the starter according to the present invention, the bracket has a retaining wall to prevent removal of the pinion seal from the output shaft when the starter motor is not activated, and the retaining wall is placed opposite the pinion retainer with respect to the pinion. The starter according to the present invention further includes an elastic member retained between the pinion movement cylinder and the pinion to provide an axial spring force. The starter according to the present invention further includes: a stepped portion on an inner peripheral surface of the pinion movement cylinder; and a retaining means, provided on the output shaft which contacts the stepped portion to restrict a sliding movement of the pinion movement cylinder when the starter motor is activated.

BRIEF DESCRIPTION OF THE DRAWINGS In the accompanying drawings: Figure 1 is a cross-sectional view showing primarily an output shaft and its vicinity of a starter motor constituting an embodiment of the present invention; and Figure 2 is a cross-sectional view, showing primarily an output shaft and its vicinity of a related starter.

Figure 1 is a cross-sectional view, partially showing a starter motor 100 which constitutes an embodiment of the present invention. The portions about a pinion movement cylinder 104 shown in Fig. 1 are different in structure from those shown in Fig. 2. In Fig. 1, the same reference numerals are applied to the members and equal or equal portions. functionally equivalent to those shown in Figure 2, so that the repeated description is omitted. A collar 12 is adjustably secured to the inner periphery of the pinion movement cylinder 104. The pinion movement cylinder 104 is slidably mounted axially and mounted on the output shaft 107 to which a rotational force of a direct current motor (D.C.) is transmitted through a planetary gear device 6. An inner clutch 8b of a clutch 8 of free rotation is formed on the lateral planetary gear device 6 (ie, the rear end portion) of this pinion movement cylinder 104. On the other hand, a straight slot 104a is formed on the outer periphery of the front end portion of the pinion movement cylinder 104. A flange portion 104c is provided which is an axially stepped support end of a helical spring 124 (i.e., an elastic member) between a slidably supported surface 104b and the straight slot 104a of the pinion movement cylinder 104. The slidably supported surface 104b is supported rotatably and slidably through a bearing 3 towards the front bracket 101. A pinion 105 having a straight slot 105a on its inner periphery is slidably mounted on the straight slot 104a. A larger cylindrical bore 105b is provided in its inner diameter than the straight groove 105a, in the side bearing 3 to the pinion 105. A flange portion 105d which is a rung axially supporting the other end of the coil spring 124 in a state in which a constant elastic force is maintained, it is formed by the cylindrical hole 105b and the straight slot 105a. A substantially cylindrical pinion detent 125 is mounted on the pinion movement cylinder 104 so that it is located adjacent the pinion 105. A tapered hole 125a having an outwardly expanding inner diameter is formed through the pinion detent 125 . The straight slot 104a of the pinion movement cylinder 104, to which the pinion detent 125 is mounted, has a groove 104d which is a retaining groove for mounting a retaining ring 127. The retaining ring 127 is an annular resilient member having an opening portion. In this way, the pinion 105 is retained on the outer periphery of the pinion movement cylinder 104 by this pinion retention means. The free-wheel clutch 8, the collar 12 and the pinion-drive cylinder 104 are assembled on the output shaft 7, and then the front bracket 101 to which the bearing 3 is placed is assembled to cover the cylinder 104 of pinion movement. After the helical spring 124 is inserted to contact the flange portion 104c of the pinion movement cylinder 104, the pinion 105 and the pinion detent 125 are mounted on the pinion movement cylinder 104. The pinion 105 and the pinion detent 125 are urged towards the bearing 3 to compress the helical spring 124 which is retained between the pinion movement cylinder 104 and the pinion 105, and then the retaining ring 127 is inserted into the groove 104d of the pinion movement cylinder 104. Since the pinion detent 125 receives the spring force of the helical spring 124 and is retained by the retainer ring 127 inserted into the spline 104d in this manner, the pinion detent 125 is prevented from being moved out of its place. A retaining wall 101a of the front bracket 101 extends towards the surface 104b slidably supported from the pinion movement cylinder 104 at a position between the pinion 105 and the bearing 3. The retaining wall 101a is provided with a predetermined space from the pinion 105 when the engine 100 is not activated (in a state shown in figure 1). This space is of such size that it prevents displacement of the pinion 105 and the removal of the pinion 105 from the pinion movement cylinder 104, which is caused due to the removal of the retaining ring 127 to retain the pinion detent 125 outside the pinion. slot 104d as a result of axial movement of pinion detent 125 and pinion 105, when pinion retainer 125 and pinion 105 receive external force during assembly of the unactivated starter motor within the engine, or the like. A portion 104f of inner periphery of enlarged diameter, which is cylindrical in area greater in diameter with respect to the coupling portion 104e to which the sleeve 12 engages, is formed on the inner peripheral surface of the pinion cylinder 104 to extend axially from the front end surface thereof over a predetermined length. Coupling portion 104e and enlarged diameter inner periphery portion 104f form a stepped portion 104g. A detent 113 for restricting the axial displacement of the pinion movement cylinder 104 is provided on the front end portion of the output shaft 107. The detent 113 is fixed to the output shaft 107 by inserting a retaining ring 114 into a slot provided on the output shaft 107. The detent 113 is positioned in a substantially confronting position with the inner periphery portion 104f of enlarged diameter of the pinion movement cylinder 104., even if the starter motor is not activated. With this arrangement, when the cylinder 104 motion pinion moves slidably forward by the lever 10 of displacement, the slidable movement of the cylinder 104 moving gear is restricted so that the 104g stepped portion is contacted with the catch 113 for stopping the pinion 105 in a position where the pinion 105 meshes with the ring gear of the motor. Since the detent 113 is located within the pinion movement cylinder 104 even when the starter motor 100 is not activated, as described above, the length of the output shaft 107 can be shortened compared to the starter motor. related, shown in Fig. 2. In the starter motor 100 constructed in this manner, since the pinion movement cylinder 104, which is assembled to the clutch 8 with free rotation and which is fitted snugly on the shaft 7 of output, is inserted into the bearing 3 from the inner side of the bracket 101 front and then only the pinion 105 is mounted on the outer periphery of the front end of the cylinder 104 moving the pinion from the front side, the outer diameter of the pinion 105 it is not influenced by the outer diameter of the surface 104b slidably supported by the pinion movement cylinder 104. Therefore, an arbitrary number of teeth can be formed on the pinion 105. It is possible not only to solve the problem of the increased size and weight found in the related starter motors in which the outer diameter of the surface 104b slidably supported must be increased in relation to the outer diameter of the pinion 105, but also the length L from the pinion 105 is increased towards the wall surface of the starter motor where it must be mounted on the mounting surface of the motor, since the force of the front bracket 101 can be markedly improved by increasing the wall thickness of the front bracket 101 correspondingly to an amount by which the outer diameter of the slidably supported surface 104b need not be increased. Therefore, the starter motor of the so-called free-spin type can be easily constructed. In addition, the length of the output shaft 107 can be shortened due to the arrangement in which one end of the output shaft 107 is constructed as the carrier of the planetary gear device 6, while the stopper 113, at the other end thereof to stop the pinion movement cylinder 104, it is placed inside the pinion movement cylinder 104. This prevents eccentric displacement of the output shaft. Accordingly, it is possible to improve the durability of the detent 113 and prevent the generation of noise. A starter according to the present invention includes: an output shaft to which a rotational force of a motor is transmitted through a planetary gear device; a pinion movement cylinder fitted snugly on the output shaft so that it is axially slidable from the output shaft; a pinion removably mounted on the outer peripheral portion of the pinion movement cylinder; a pinion retaining means for retaining the pinion on the outer peripheral portion of the pinion movement cylinder; and a bracket that supports rotatably and slidably the pinion movement cylinder. Therefore, the external diameter of the pinion can be changed by a simple construction without any change in the outer diameter of the surface slidably supported by the pinion movement cylinder and in this way the number of teeth in the pinion can be freely selected. In the starter according to the present invention, the pinion retaining means includes a pinion retainer provided in contact with the pinion, and a retaining ring fixed to a retaining groove provided on the outer peripheral portion of the pinion cylinder. pinion movement. Therefore, the pinion can be mounted removably on the outer peripheral portion of the pinion movement cylinder, easily. In the starter according to the present invention, the bracket has a retaining wall to prevent removal of the pinion retainer from the output shaft when the starter motor is not activated, and the retaining wall is positioned opposite the pinion retainer with respect to the pinion. Therefore, this retaining wall prevents the pinion from moving, so it avoids the removal of the pinion. The starter according to the present invention includes an elastic member retained between the pinion movement cylinder and the pinion to provide an axial spring force. Therefore, the elastic force of the elastic member is applied to the pinion retainer so as to further prevent the movement of the pinion retainer, thereby further preventing the pinion from being removed. The starter according to the present invention further includes: a stepped portion on an inner peripheral surface of the pinion movement cylinder; and retaining means provided on the output shaft contacting the stepped portion to prevent a slidable movement of the pinion movement cylinder when the starter motor is activated. Therefore, the pinion stop moves while being confronted with the inner peripheral surface of the pinion movement cylinder, and therefore the length of the output shaft can be shortened.

Claims (11)

1. A starter motor, characterized in that it comprises: an output shaft to which rotational force is transmitted from a motor through a planetary gear device; a pinion movement cylinder, fitted snugly on the output shaft so that it is axially slidable from the output shaft; a pinion removably mounted on an outer peripheral portion of the pinion movement cylinder; a pinion retaining means for retaining the pinion on the outer peripheral portion of the pinion movement cylinder; and a bracket that supports the pinion movement cylinder rotatably and slidably.

2. The starter motor, according to claim 1, characterized in that the pinion retaining means includes a pinion retainer provided in contact with the pinion, and a retaining ring fixed to a retaining groove provided on the outer peripheral portion of the pinion. pinion movement cylinder.

3. The starter motor, according to claim 2, characterized in that the bracket has a retaining wall to prevent the removal of the pinion retainer from the output shaft when the starter motor is not activated, the retention wall is placed opposite from the pinion retainer with respect to the pinion.

4. The starter motor according to claim 3, characterized in that it further comprises an elastic member retained between the pinion movement cylinder and the pinion, to provide an axial elastic force.

5. The starter motor, according to claim 4, characterized in that it further comprises: a stepped portion on an inner peripheral surface of the pinion movement cylinder; and retaining means, provided on the output shaft which contact the stepped portion to prevent a slidable movement of the pinion movement cylinder when the starter motor is activated.

6. The starter motor, according to claim 1, characterized in that the bracket has a retaining wall to prevent the removal of the pinion retainer from the output shaft when the starter motor is not activated, the retention wall is placed opposite from the pinion retainer with respect to the pinion.

7. The starter motor, according to claim 6, characterized in that it further comprises an elastic member retained between the pinion movement cylinder and the pinion, to provide an axial elastic force.

8. The starter motor, according to claim 7, characterized in that it further comprises: a stepped portion on an inner peripheral surface of the pinion movement cylinder; and retaining means provided on the output shaft which contact the stepped portion to prevent sliding movement of the pinion movement cylinder when the starter motor is activated.

9. The starter motor, according to claim 1, characterized in that it further comprises an elastic member retained between the pinion movement cylinder and the pinion, to provide an axial elastic force.

10. The starter motor, according to claim 9, characterized in that it further comprises: a stepped portion on an inner peripheral surface of the pinion movement cylinder; and retaining means provided on the output shaft contacting the stepped portion to restrict the sliding movement of the pinion movement cylinder when activated to the starter motor.

11. The starter motor, according to claim 1, characterized in that it further comprises: a stepped portion on an inner peripheral surface of the pinion movement cylinder; and retaining means, provided on the output shaft that contact the stepped portion to restrict the sliding movement of the pinion movement cylinder when the starter motor is activated.